Combination hydraulic and weight-set dual string well packers



Aug. 25, 1964 c. B. COCHRAN 3,145,777

COMBINATION HYDRAULIC AND WEIGHT-SET DUAL STRING WELL PACKERS Filed Aug. 6, 1962. 3 Sheets-Sheet 1 ATTORNEY Aug. 25, 1964 c. B. COCHRAN 3,145,777

CDMBINATION HYDRAULIC AND WEIGHT-SET DUAL STRING WELL PAcxERs 3 Sheets-Sheet 2 Filed Aug. 6, 1962 CHULE/G/- B. COCHRAN 0 5' 1N V EN TOR. 017i 4' BY u ATTORNE y Al1g- 25, 1964 c. B. cocHRAN 3,145,777

COMBINATION HYDRAULIC AND WEIGHT-SET DUAL STRING WELL PACKERS Filed Aug. 6, 1962 3 Sheets-Sheet 3 C H UDL E/G/ B. COCHRAN IN V EN TOR.

ATTORNEY United States Patent O 3,145# 77 COMBWATON HYDRAULIC AND WEIGHT-SET DUAL STRING WELL PACKERS Chudleigh B. Cochran, Houston, Tex., assigner to Cicero C. Brown, Houston, Tex. Filed Ang. 6, 1962, Ser. No. 215,126 7 Claims. (Cl. 166-122) This invention relates to Well packers and more particularly to dual pipe string packers.

Many wells are presently completed to ilow from at least two different producing zones and such wells are commonly referred to as dual production or dual completion wells. In such cases, the zones are connected to ow simultaneously, but separately, to the surface and for that purpose separate strings of pipe are employed to connect the respective formations to the well head for independent production from the well.

In connection with such dual completion wells, it is necessary to set at least two packers, one between the two producing formations and one above the uppermost producing formation to separate the formations from one another and to lead two separate pipe strings through the upper one of the two packers vby suitable arrangement which will provide the separate and independent flow arrangements desired.

Such dual pipe string packers generally involve considerable dilliculty in manipulation and setting and are usually quite complicated in their construction, giving rise to numerous diiliculties in their employment.

Accordingly, it is a primary object of this invention to provide a dual pipe string packer of a relatively simple form which can be set and released with a minimum amount of diiculty.

An important object of this invention is to provide a dual pipe string packer which may be set by hydraulic pressure and which, in the event of failure of the hydraulic pressure mechanism, may be set by application of weight thereto.

A further object is the provision of a dual pipe string packer which is releasable by straight upward pull applied through one of the pipe strings to which it is connected.

Yet another object is to provide a dual pipe string packer which is settable by hydraulic pressure and releasable by an upward pull applied =to one of the pipe strings and which includes structure by which rotation of one of the pipe strings may be effected through the packer to release the packer or other tool in the well below the dual pipe string packer.

Other and more specific objects and advantages of this invention will become more readily apparent from the following detailed description when read in conjunction with the accompanying drawing which illustrates one useful embodiment in accordance with this invention.

In the drawing:

FIG. l is a longitudinal sectional view of a dual pipe string packer in accordance with this invention shown in a well casing in its unset condition;

FIG. 2 is a view similar to FIG. 1, showing the packer in set position;

FIGS. 3 and 4 are views similar to FIG. 2, showing the parts of the packer at two stages during release of the packer;

FIG. 5 is an elevational view, partly in section, illustrating some of the details of the packer;

FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 1; and

FIG. 7 is a cross-sectional View taken along line 7--7 of FIG. 1.

In the drawing:

There is shown a well casing C which conventionally lines the bore of a well which, it will be understood, eX-

3,145,777 Patented Aug. 25, 1964 ice tends through at least two producing zones which are to be produced separately by means of the packer herein to be described.

A pack assembly in accordance with this invention, designated generally by the letter P, is shown in the bore of casing C. Packer assembly P includes upper and lower body sections, designated generally by the numerals 10 and 11, respectively, between which is mounted an annular resilient seal element 13 which is axially compressible between the upper and lower body sections to radially expand the same to seal with the wall of casing C. Packer P is provided with a pair of parallel, longitudinally extending bores 14 and 15 adapted to receive first and second tubular mandrels 16 and 17, respectively. Mandrel 16 extends through both upper and lower body sections 10 and 11 and is adpted for connection into a first pipe string P1 which extends to the top of the well bore (not shown), and to a lower packer (not shown) conventionally disposed in well casing C between the two formations from which production is to be separately delivered to the surface. As shown, the lower end of mandrel 16 is threadedly received in a socket S formed in the end of the lower portion of pipe string P1 and the upper end of mandrel 16 is connected into the lower end of the upper portion of pipe string P1.

Upper body section 10 comprises two telescopically connected elements, one element being a sleeve piston 2i) having bores 14a and 15a coaxial with bores 14 and 15, respectively, and by means of which the piston is slidably disposed on both mandrels 16 and 17 in abutting engagement with the upper end of seal element 13, and the other element being a cylinder head 21 mounted on both mandrels 16 and 17 above piston 20 and provided with a cylindrical sleeve or skirt 22 which slidably surrounds piston 20. The latter is provided with an external shoulder 23h engageable by the lower end of skirt 22 to limit the downward movement of the cylinder head relative to fthe piston to provide therebetween the expansible pressure chamber 31. Cylinder head 21 is provided with a through bore 14h coaxial with bore 14 and through which mandrel 16 slidably extends. An internally threaded bore 15b is provided in the lower end of cylinder head 21 coaxial with bore 15 and communicates through a slightly reduced diameter opening 23a with a coaxial cylindrical socket 23 which extends to the upper end of the cylinder head.

The upper end of mandrel 17 projects upwardly from bore 15 and is threadedly secured in bore 15b to thereby secure mandrel 17 to cylinder head 21. The lower end of mandrel 17 projects below lower body portion 11 and is threadedly received in a threaded box 24 provided in the upper end of an extension nipple 25 having an internal shoulder 26 in the bore thereof for engaging a ball 27 or other conventional plugging device suitable for closing off the bore of mandrel 17 for purposes to be described hereinafter.

Socket 23 is adapted to slidably receive a latching head 28 carried by the lower end of a second pipe string P2 which extends from the surface to the packer for conducting well fluid from one of the producing zones t0 the surface. Latching head 28 carries a plurality of detents 29 which are biased to latch into a latching groove 3l) provided in the wall of socket 23 to thereby provide a generally conventional form of straight-pull latch by means of which pipe string P2 may be withdrawn from the packer by a straight upward pull. A latching head such as that herein described is disclosed in a copending application, Serial No. 756,552, filed August 22, 1958, by Cicero C. Brown and Chudleigh B. Cochran.

Cylinder head 21, skirt 22, piston 20 and mandrels 16 and 17 cooperate to form the expansible pressure chamber 31 between cylinder head 21 and the upper end of piston 20. A suitable seal packing 32 is provided between the exterior of piston 20 and skirt 22 near the upper end of the piston. Longitudinally spaced pairs of seal packings 33-33 and 34-34 are provided between piston 20 and the exteriors of mandrels 16 and 17, respectively, to provide spaced fluid-tight seals between the piston and the respective mandrels. A plurality of radial ports 35 are provided through the wall of mandrel 16 at a point such that when the packer is in unset or retracted position (FIG. 1), the ports 35 will be between seal packings 33-33 and will be movable to a point above the upper one of the seal packings 33 upon relative upward movement of mandrel 16 as during release of the device, as will appear subsequently.

Ports 36 are provided through the wall of mandrel 17 at points between packings 34 and are adapted to provide luid pressure communication from the bore of mandrel 17 with the end of a duct 38 arranged to extend through the body of piston 20 to the upper end thereof into communication with pressure chamber 31. A check valve 39 is disposed in duct 38 to prevent return flow of uid from chamber 31. Shear screws 40 extend through skirt 22 into the exterior of piston 20 to initially secure the cylinder to the piston in the relatively retracted position, as seen in FIG. 1.

Lower body section 11 includes an expander member 41 slidably disposed on mandrels 16 and 17 in abutting relation to the lower end of seal element 13, expander member 41 having bores 14C and 15C, respectively, registering with bores 14 and 15 for this purpose. Expander 41 is provided with downwardly and inwardly tapering slip-engaging surfaces 42 on which are slidably disposed conventional wedge-shaped wall-gripping slips 43, as best seen in FIG. 5, which will be urged radially outwardly upon upward relative longitudinal movement between the slips and surfaces 42. The lower ends of slips 43 are secured for radial sliding movement in an annular slip cage 44 which is disposed for longitudinal sliding movement on mandrels 16 and 17 having bores 14d and 15d, respectively, registering with bores 14 and 15 for this purpose. Slips 43 and slip cage 44 together constitute the anchor elements of the device. A relatively strong shear screw 45 extends through the wall of cage 44 and projects into an annular groove 46 provided in the exterior of mandrel 16 whereby the slip cage may be initially secured against longitudinal movement relative to mandrel 16 while permitting rotation of the latter relative to the slip cage where such rotation of the mandrel may be desirable.

Slips 43 are initially secured in retracted position on surfaces 42 by means of shear screws 47. Bore 14a` of expander member 41 is counterbored from its lower end to provide the internal downwardly facing shoulder 48. A lock ring 49 is mounted in the exterior of mandrel 16 to normally project therefrom and form an upwardly facing shoulder adapted to engage shoulder 4S at a stage in the operation of the device as will be described subsequently. Lock ring 49 is positioned on mandrel 16 at a point below shoulder 48 and in the normally retracted positions of the parts as shown in FIG. l will be seated in a counterbore 50 extending from the upper end of bore 14d.

A pick-up ring 51 having longitudinal bores 14e and e, respectively, coaxial with bores 14 and 15, is slidably disposed about the lower end of mandrel 16 and extension nipple 25. Downward movement of pick-up ring 51 is limited by engagement with the upper end of socket S, as shown particularly in FIG. l, and its upward travel along the mandrels is limited by a downwardly facing shoulder 52 provided about nipple 25 at the lower end of box 24.

Operation of the device is as follows: The packer P, assembled as shown in FIG. 1 but without pipe string P2 connected thereto, will be lowered into the well bore and connected to a lower packer (not shown). This may be done by the use of any conventional type of connecting element carried on pipe P1 below packer P and may constitute a conventional sliding Stringer or a connection member which is operable by relative rotation. In structures employing the latter type of connection, the rotatable connection provided by shear screw 45 and groove 46 permits rotation of pipe string P1 relative to packer P, whether the latter is in set or unset condition, and similarly, permits release from a lower packer by rotation where such rotation is required.

When packer P is in position, pipe string P2, carrying latching head 28, will be introduced into the well and the latching head inserted into socket 23. Thereupon, ball 27 or other plugging device will be dropped or pumped through pipe string P2 until it engages shoulder 26 closing olf the bore of pipe string P2 and of mandrel 17. Thereupon, continued pumping of fluid into pipe string P2 will build up pressure in the bore of mandrel 17. This fluid pressure will then be transmitted through ports 36 and duct 38 into pressure chamber 31. The pressure will then act on the upper end of piston 20 urging the latter downwardly against seal element 13. This movement will, of course, be opposed by the resistance offered by lower body section 11 through the interconnections to slip cage 44 which is seated on the upper end of box 24 of extension nipple 25. The downward pressure exerted against seal element 13 will be transmitted to expander 41 with suicient force to break shear screws 47, allowing the expander to move downwardly relative to slips 43. This will urge the latter outwardly into engagement with the wall of casing C, stopping further downward movement of the expander. The continued downward pressure on piston 20 will then cause expansion of seal element 13, as shown in FIG. 2, setting the packer. Check valve 39 will normally act to retain the uid pressure in chamber 31 to maintain the setting pressure on the packer. However, should it fail, the packer can be maintained in set position by simply applying weight to pipe string P2, thereby moving cylinder head 21 downwardly until skirt 22 engages shoulder 23h, whereupon the imposition of the weight of pipe string P2 will be transmitted to the upper end of seal element 13. As cylinder head 21 is slidable on mandrel 16, this auxiliary method of maintaining the packer in set position may be effected.

When the packer has been set, as described, ball 27 or such other plugging device as may have been used, may be removed in any conventional and well-known manner, and the bore of pipe string P2 opened to production from one earth zone while pipe string P1 is in communication with a different producing zone.

To release the packer, an upward pull is taken on pipe string P1 with sutlicient force to break shear pin 45 (FIG. 3), thereupon mandrel 16 may be elevated relative to the packer until ports 35 move upwardly above the uppermost seal packing 33 and into communication with pressure chamber 31, thereby relieving the iluid pressure from pressure chamber 31 into the bore of mandrel 16 and pipe string P1. With the pressure thus relieved, seal element 13 tends to retract and to be released from engagement with the wall of casing C. However, continued upward pull applied to pipe string P1 will bring lock ring 49 into engagement with shoulder 48 and this engagement will act to pull expander 41 upwardly from under slips 43 and cause their retraction from engagement with the wall of casing C (FIG. 3). Slips 43, as shown in FIG. 6, are provided with lateral tongues 53 engageable in corresponding grooves 54 formed adjacent surfaces 42 to retain the slips on the expander while permitting the relative longitudinal movement therebetween.

With the slips thus pulled away from the casing and seal element 13 retracted, continued upward movement of pipe string P1 will bring pick-up ring 51 up against shoulder 52 and will thereby support the lower body section on the mandrels as the structure is withdrawn from the well. Of course, it will be understood that pipe string P2 will have been pulled out of its connection with the packer before the release operations are undertaken.

From the foregoing, it will be seen that I have provided an improved form of packer which fulfills the various objects and advantages previously referred to. It will be understood that various other alterations and modifications may be made in the details of the illustrative embodiment within the scope of the appended claims but without departing from the spirit of this invention.

What I claim and desire to secure by Letters Patent is:

1. A dual pipe string well packer, comprising upper and lower body sections having parallel first and second longitudinal passages therethrough, first and second tubular mandrels slidably received in the respective passages and adapted for connection respectively to a first pipe string and to said upper body section, a resilient seal portion disposed about the mandrels between the body sections and adapted to be radially expanded by end-wise compression therebetween to seal with a surrounding well wall, said lower body section including a downwardly and inwardly tapering expander means slidably mounted on the mandrels beneath the seal portion and movable downwardly therewith, anchor elements including radially movable slips mounted on the mandrels below the expander means expansibly engageable by the expander means in response to relative downward movement of the upper body section to engage the well wall whereby further downward movement of the upper body section will produce said end-wise compression of said seal portion, said upper body section comprising a piston member slidably disposed on the mandrels in abutting engagement with the upper end of said seal portion, a cylinder mounted on the mandrels slidably enclosing the piston member and cooperating therewith to define an expansible pressure chamber, cooperating conduit means disposed in the piston member and in said second mandrel to provide fluid pressure communication between said pressure chamber and the bore of said second mandrel for directing fluid pressure from said second mandrel into said pressure chamber to move said piston member downwardly whereby to set the packer, and releasable means initially connecting said anchor elements to said first mandrel releasable by straight upward pull applied to the first mandrel to release the packer.

2. A dual pipe string well packer according to claim 1 wherein said releasable means comprises shear pin means `securing the anchor elements to said first mandrel, and pressure relief ports through the wall of said first mandrel movable into communication with said pressure chamber by upward movement of said first mandrel following breaking of said shear pin means.

3. ln ya dual pipe string well packer according to claim 1, check valve means in said conduit means arranged to prevent reverse flow of pressure fluid from said chamber to said second mandrel.

4. A dual pipe string well packer, comprising, upper and lower body sections having parallel first and second longitudinal passages therethrough, first and second tubular mandrels slidably received in the respective passages and adapted `for connection respectively Ito ta first pipe string and to said upper body section, a resilient seal portion disposed about the mandrels between said body sections and adapted to be radially expanded by end-wise compression therebetween to -seal with a surrounding well wall, said lower body section including a downwardly and inwardly tapering expander means slidably mounted on the mandrels beneath the seal portion and movable downwardly therewith, ia slip cage slidably disposed about the mandrels below the expander means, radially movable slips mounted on the slip cage expansibly engageable by the expander means in response to relative downward movement of the upper body section to engage the well wall whereby further downward movement of the upper body section will produce said end-wise compression of said seal portion, said upper body section comprising a piston member slidably disposed on the mandrels in abutting engagement with the upper end of said seal portion, a cylinder mounted on the mandrels above the piston member and cooperating therewith to define an expansible pressure chamber, cooperating conduit means disposed in the piston member and in said second mandrel to provide fluid pressure communication between said pres- :sure chamber and the bore of said second mandrel for directing fiuid pressure in said second mandrel into said pressure chamber to move said piston member downwardly whereby to set the packer, and shear pin means initially securing said slip cage to said first mandrel and breakable by straight upward pull applied to the rst mandrel to release the packer.

5. In a dual pipe string well packer according to claim 4, check valve means in said conduit means arranged to prevent reverse 4fiow of pressure fluid from said chamber t-o said second mandrel.

6i. In a dual pipe string well packer according to claim 4, pressure relief ports through the wall of said first mandrel movable into communication with said pressure chamber by upward movement of the first mandrel following breaking of said shear pins.

7. A dual pipe string well packer, comprising, upper and lower body sections having parallel first and second longitudinal passages therethrough, first and second tubular mandrels slidably received in the respective passages and adapted for connection respectively to a first pipe string and to said upper body section, a resilient seal portion disposed about the mandrels between the body sections and adapted to be radially expanded by end-wise compression therebetween to seal with a surrounding well wall, said lower body section including a downwardly and inwardly tapering expander means slidably mounted on the mandrels beneath the seal portion and movable downwardly therewith, anchor elements including radially movable slips mounted on the mandrels below the expander means expansible engageable by the expander means in response to relative downward movement of the upper body section to engage the well wall whereby further downward movement of the upper body section will produce said end-wise compression of said seal portion, said upper body section comprising a piston member slidably disposed on the mandrels in abutting engagement with the upper end of said seal portion, a cylinder head mounted on the mandrels above the piston member and carrying a cylinder sleeve slidably enclosing the piston member and cooperating therewith to define an expansible pressure chamber, cooperating conduit means disposed in the piston member and in the second mandrel to provide fiuid pressure communication between said pressure chamber and the bore of said second mandrel for directing fiuid pressure from said second mandrel into said pressure chamber to move said piston member downwardly whereby to set the packer, a tubular socket in said cylinder head for receiving said second pipe string operable to transmit weight of said second pipe string to said seal portion to provide an alternative source of endwise compression thereto, and releasable means initially connecting said anchor elements to said first mandrel operable by straight upward pull applied to the first mandrel to release the packer.

References Cited in the le of this patent UNITED STATES PATENTS 2,903,066 Brown Sept. 8, 1959 2,965,173 Brown Dec. 20, 1960 3,094,168 Myers June 18, 1963 

1. A DUAL PIPE STRING WELL PACKER, COMPRISING UPPER AND LOWER BODY SECTIONS HAVING PARALLEL FIRST AND SECOND LONGITUDINAL PASSAGES THERETHROUGH, FIRST AND SECOND TUBULAR MANDRELS SLIDABLY RECEIVED IN THE RESPECTIVE PASSAGES AND ADAPTED FOR CONNECTION RESPECTIVELY TO A FIRST PIPE STRING AND TO SAID UPPER BODY SECTION, A RESILIENT SEAL PORTION DISPOSED ABOUT THE MANDRELS BETWEEN THE BODY SECTIONS AND ADAPTED TO BE RADIALLY EXPANDED BY END-WISE COMPRESSION THEREBETWEEN TO SEAL WITH A SURROUNDING WELL WALL, SAID LOWER BODY SECTION INCLUDING A DOWNWARDLY AND INWARDLY TAPERING EXPANDER MEANS SLIDABLY MOUNTED ON THE MANDRELS BENEATH THE SEAL PORTION AND MOVABLE DOWNWARDLY THEREWITH, ANCHOR ELEMENTS INCLUDING RADIALLY MOVABLE SLIPS MOUNTED ON THE MANDRELS BELOW THE EXPANDER MEANS EXPANSIBLY ENGAGEABLE BY THE EXPANDER MEANS IN RESPONSE TO RELATIVE DOWNWARD MOVEMENT OF THE UPPER BODY SECTION TO ENGAGE THE WELL WALL WHEREBY FURTHER DOWNWARD MOVEMENT OF THE UPPER BODY SECTION WILL PRODUCE SAID END-WISE COMPRESSION OF SAID SEAL PORTION, SAID UPPER BODY SECTION COMPRISING A PISTON MEMBER SLIDABLY DISPOSED ON THE MANDRELS IN ABUTTING ENGAGEMENT WITH THE UPPER END OF SAID SEAL PORTION, A CYLINDER MOUNTED ON THE MANDRELS SLIDABLY ENCLOSING THE PISTON MEMBER AND COOPERATING THEREWITH TO DEFINE AN EXPANSIBLE PRESSURE CHAMBER, COOPERATING CONDUIT MEANS DISPOSED IN THE PISTON MEMBER AND IN SAID SECOND MANDREL TO PROVIDE FLUID PRESSURE COMMUNICATION BETWEEN SAID PRESSURE CHAMBER AND THE BORE OF SAID SECOND MANDREL FOR DIRECTING FLUID PRESSURE FROM SAID SECOND MANDREL INTO SAID PRESSURE CHAMBER TO MOVE SAID PISTON MEMBER DOWNWARDLY WHEREBY TO SET THE PACKER, AND RELEASABLE MEANS INITIALLY CONNECTING SAID ANCHOR ELEMENTS TO SAID FIRST MANDREL RELEASABLE BY STRAIGHT UPWARD PULL APPLIED TO THE FIRST MANDREL TO RELEASE THE PACKER. 